U.S. patent number 10,153,870 [Application Number 15/882,114] was granted by the patent office on 2018-12-11 for method and apparatus for operating supplementary cells in licensed exempt spectrum.
This patent grant is currently assigned to InterDigital Patent Holdongs, Inc.. The grantee listed for this patent is InterDigital Patent Holdings, Inc.. Invention is credited to Erdem Bala, Mihaela C. Beluri, Douglas R. Castor, Amith V. Chincholi, Angelo A. Cuffaro, Yuying Dai, Alpaslan Demir, Rocco Di Girolamo, Martino M. Freda, Jean-Louis Gauvreau, Joseph Gredone, Zinan Lin, Liangping Ma, Joseph M. Murray, Debashish Purkayastha, Athmane Touag, Rui Yang, Chunxuan Ye.
United States Patent |
10,153,870 |
Gauvreau , et al. |
December 11, 2018 |
**Please see images for:
( Certificate of Correction ) ** |
Method and apparatus for operating supplementary cells in licensed
exempt spectrum
Abstract
A method and apparatus for operating supplementary cells in
licensed exempt (LE) spectrum. An aggregating cell operating in a
frequency division duplex (FDD) licensed spectrum is aggregated
with a LE supplementary cell operating in a time sharing mode for
uplink (UL) and downlink (DL) operations. The LE supplementary cell
may be an FDD supplementary cell dynamically configurable between
an UL only mode, a DL only mode, and a shared mode, to match
requested UL and DL traffic ratios. The LE supplementary cell may
be a time division duplex (TDD) supplementary cell. The TDD
supplementary cell may be dynamically configurable between multiple
TDD configurations. A coexistence capability for coordinating
operations between the LE supplementary cell with other systems
operating in the same channel is provided. Coexistence gaps are
provided to measure primary/secondary user usage and permit other
systems operating in the LE supplementary cell channel to access
the channel.
Inventors: |
Gauvreau; Jean-Louis (La
Prairie, CA), Freda; Martino M. (Laval,
CA), Lin; Zinan (Basking Ridge, NJ), Murray;
Joseph M. (Schwenksville, PA), Ye; Chunxuan (San Diego,
CA), Bala; Erdem (East Meadow, NY), Beluri; Mihaela
C. (Jericho, NY), Castor; Douglas R. (Norristown,
PA), Chincholi; Amith V. (Sunnyvale, CA), Cuffaro; Angelo
A. (Laval, CA), Dai; Yuying (Brossard,
CA), Demir; Alpaslan (East Meadow, NY), Gredone;
Joseph (Chalfont, PA), Yang; Rui (Greenlawn, NY), Ma;
Liangping (San Diego, CA), Di Girolamo; Rocco (Laval,
CA), Purkayastha; Debashish (Collegeville, PA),
Touag; Athmane (Laval, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
InterDigital Patent Holdings, Inc. |
Wilmington |
DE |
US |
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Assignee: |
InterDigital Patent Holdongs,
Inc. (Wilmington, DE)
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Family
ID: |
45755529 |
Appl.
No.: |
15/882,114 |
Filed: |
January 29, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20180152268 A1 |
May 31, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15219179 |
Jan 30, 2018 |
9882684 |
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13984180 |
Aug 16, 2016 |
9419776 |
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PCT/US2012/024079 |
Feb 7, 2012 |
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61560571 |
Nov 16, 2011 |
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61440288 |
Feb 7, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L
5/0055 (20130101); H04W 16/24 (20130101); H04L
5/143 (20130101); H04L 5/14 (20130101); H04L
5/1469 (20130101); H04L 5/06 (20130101); H04L
1/1893 (20130101); H04L 5/0032 (20130101); H04W
72/082 (20130101); H04W 16/14 (20130101); H04L
1/1861 (20130101); H04W 72/0446 (20130101); H04W
28/16 (20130101); H04L 1/1812 (20130101); H04W
72/0453 (20130101) |
Current International
Class: |
H04L
1/18 (20060101); H04L 5/00 (20060101); H04W
16/24 (20090101); H04L 5/14 (20060101); H04L
5/06 (20060101); H04W 72/08 (20090101); H04W
72/04 (20090101); H04W 16/14 (20090101); H04W
28/16 (20090101) |
References Cited
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1578525 |
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Jun 2011 |
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JP |
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May 2012 |
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JP |
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2012-516108 |
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Jul 2012 |
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JP |
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Sep 2012 |
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JP |
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Jan 2013 |
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JP |
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WO |
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WO |
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WO 2010/129295 |
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Nov 2010 |
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WO |
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WO 2011/014002 |
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Feb 2011 |
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WO |
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Primary Examiner: Towfighi; Afshawn M
Attorney, Agent or Firm: Condo Roccia Koptiw LLP
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser.
No. 15/219,179, filed Jul. 25, 2016, which is a continuation of
U.S. patent application Ser. No. 13/984,180, filed Jan. 16, 2014,
now U.S. Pat. No. 9,419,776 issued Aug. 16, 2016, which is the
National Stage Entry under 35 U.S.C. .sctn. 371 of Patent
Cooperation Treaty Application No. PCT/US2012/024079, filed Feb. 7,
2012, which claims the benefit of U.S. provisional application No.
61/440,288, filed Feb. 7, 2011, and U.S. provisional application
No. 61/560,571, filed Nov. 16, 2011 the contents of which are
hereby incorporated by reference herein.
Claims
What is claimed is:
1. A method of carrier aggregation, comprising: operating on a
frequency division duplex (FDD) primary cell aggregated with a time
division duplex (TDD) supplementary cell; receiving a downlink (DL)
transmission; determining a timing based on the timing used for the
primary cell for hybrid automatic repeat request (HARQ) feedback
for the DL transmission; and sending the HARQ feedback on the FDD
primary cell based on the determined timing.
2. The method of claim 1, wherein the HARQ feedback timing is set
for a sub-frame (n+4).
3. The method of claim 1, wherein the DL transmission is on the TDD
supplementary cell.
4. The method of claim 1, wherein the DL transmission is on the FDD
primary cell.
5. The method of claim 1, further comprising sending positive
acknowledgement (ACK)/negative acknowledgement (NACK) n+4 subframes
following the DL transmission.
6. The method of claim 1, wherein the DL HARQ feedback is carried
in a physical UL control channel (PUCCH).
7. The method of claim 6, wherein the PUCCH is on the FDD primary
cell.
8. The method of claim 1, wherein multiple TDD supplementary cells
are aggregated, each TDD supplementary cell being one of
independently or dependently configured.
9. A wireless transmit/receive unit (WTRU), comprising: a
processor; and a memory having stored instructions that when
executed by the processor cause the WTRU to: operate on a FDD
primary cell aggregated with a TDD supplementary cell; receive a DL
transmission on the TDD supplementary cell; determine a timing for
HARQ feedback for the DL transmission; and send the HARQ feedback
on the FDD primary cell based on the determined timing.
10. The WTRU of claim 9, wherein, wherein the HARQ feedback timing
is set for a sub-frame (n+4).
11. The WTRU of claim 9, wherein the WTRU sends an ACK/NACK n+4
subframes following the DL transmission.
12. A method of carrier aggregation, comprising: operating on a FDD
primary cell aggregated with a TDD supplementary cell; sending an
uplink (UL) transmission in a sub-frame (n); determining a timing
for hybrid automatic repeat request (HARQ) feedback for the UL
transmission; receiving the HARQ feedback on the FDD primary cell;
and associating the HARQ feedback with the UL transmission based on
the determined timing.
13. The method of claim 12, wherein the HARQ feedback timing is set
for a sub-frame (n+4).
14. The method of claim 12, wherein the UL transmission is on the
TDD supplementary cell.
15. The method of claim 12, wherein the UL transmission is on the
FDD primary cell.
16. The method of claim 12, further comprising receiving an
ACK/NACK n+4 subframes following the UL transmission.
17. The method of claim 12, wherein UL HARQ feedback is carried in
a modified physical HARQ indicator channel (PHICH).
18. The method of claim 17, wherein the PHICH is carried on the
primary cell.
19. The method of claim 12, wherein multiple TDD supplementary
cells are aggregated, each TDD supplementary cell being one of
independently or dependently configured.
Description
FIELD OF INVENTION
This application is related to wireless communications.
BACKGROUND
As the number of mobile users continues to increase, additional
licensed band spectrum is needed to support these mobile users.
However, licensed band spectrum is not readily available and may be
very expensive to acquire. Therefore, it is highly desirable to
deploy cellular radio access technologies (RATs) such as, for
example, long term evolution (LTE), in newly available spectrum
such as television white space (TVWS) or unlicensed bands, which
may be collectively referred to as licensed exempt (LE)
spectrum.
Operation of the deployed RATs in LE spectrum may be modified to
mitigate uncoordinated spectrum usage, as well as to support uplink
(UL) and downlink (DL) operation without the need for fixed
frequency duplex operation. For example, the spacing between
available channels in TVWS may depend on the current location and
use of the TVWS by primary users in the vicinity. Furthermore, some
areas may only have one TVWS channel available, which may result in
having to operate and provide both UL and DL resources on a single
TVWS channel. In addition, operation over LE spectrum may be
subject to the lower reliability of these channels, (as compared to
operation over the licensed bands), and to frequently stop
operation on a given channel due to high level interference, the
arrival of a primary incumbent, coexistence database decisions, and
the like.
Current carrier aggregation (CA) solutions may not be appropriate
for these LE bands since the aggregated carriers may rely on the
use of licensed secondary component carriers (SCCs), which are
reliable and are used by operators with confidence. However, the
aggregation scenarios they support may be rather restrictive, (for
example, usually implementing DL scenarios where the number of DL
SCCs may exceed the number of UL SCCs used in the aggregation).
SUMMARY
A method and apparatus for operating supplementary cells in
licensed exempt (LE) spectrum. Supplementary cells may be deployed
by a system to use LE bands, for example, opportunistic,
sublicensed, television white space (TVWS), and industrial,
scientific and medical (ISM) bands. The supplementary cells may be
aggregated with an aggregrating cell including, for example,
primary cells and/or a secondary cells. In particular, the primary
cell operating in a frequency division duplex (FDD) licensed
spectrum may be aggregated with a LE supplementary cell operating
in a time sharing mode for uplink (UL) and downlink (DL)
operations. In one example, the LE supplementary cell may be an FDD
supplementary cell dynamically configurable between an UL only
mode, a DL only mode, and a shared mode, to match requested UL and
DL traffic ratios. In another example, the LE supplementary cell
may be a time division duplex (TDD) supplementary cell. The TDD
supplementary cell may be dynamically configurable between multiple
TDD configurations. In addition, a coexistence capability for
coordinating operations between a LE supplementary cell with other
systems operating in the same channel, possibly using another radio
access technology (RAT) may be provided. Coexistence gaps may be
provided to measure primary and secondary user usage and permit
other systems operating in the same channel as the LE supplementary
cell to access the channel.
BRIEF DESCRIPTION OF THE DRAWINGS
A more detailed understanding may be had from the following
description, given by way of example in conjunction with the
accompanying drawings wherein:
FIG. 1A shows an example communications system in which one or more
described embodiments may be implemented;
FIG. 1B shows an example wireless transmit/receive unit WTRU) that
may be used within the communications system shown in FIG. 1A;
FIG. 1C shows an example radio access network and an example core
network (CN) that may be used within the communications system
shown in FIG. 1A;
FIG. 2 shows an example of television (TV) band spectrum usage;
FIG. 3 shows an example of licensed exempt carrier aggregation
deployment.
FIG. 4 shows an example of licensed exempt carrier aggregated with
a long term evolution (LTE) primary cell;
FIG. 5 shows an example of a high level advanced LTE spectrum
solution (ALTESS) operation;
FIG. 6 shows an example of dynamic frequency division duplex (FDD)
operating modes;
FIG. 7 shows example solutions for different procedures impacting
supplementary component carriers (SuppCCs) in a downlink (DL)-only
operating mode;
FIG. 8 shows example solutions for different procedures impacting
SuppCCs in an uplink (UL)-only operating mode;
FIG. 9 shows an example of timing alignment or a 4DL:4UL related
pattern;
FIGS. 10A and 10B show examples of hybrid automatic repeat request
(HARQ) details for repeat-8 patterns, (a primary cell with an HARQ
round-trip-time (RTT) of 8 sub-frames);
FIGS. 11A and 11B show examples of HARQ details for a repeat-16
pattern, (a primary cell with an HARQ RTT of 16 sub-frames);
FIG. 12 shows an example of dynamically changing the direction of
aggregation through a radio resource control (RRC) reconfiguration
sent over a primary carrier;
FIG. 13 shows an example of dynamically changing the direction of
aggregation through a medium access control (MAC) control element
(CE) command sent over a primary carrier;
FIG. 14 shows an example of a licensed band frequency division
duplex (FDD) primary cell containing both UL and DL component
carriers (CCs) aggregated with a time division duplex (TDD)
supplementary carrier; and
FIG. 15 shows the physical channels that are supported on each
carrier of a system supporting a licensed exempt operation.
DETAILED DESCRIPTION
FIG. 1A shows an example communications system 100 in which one or
more described embodiments may be implemented. The communications
system 100 may be a multiple access system that provides content,
such as voice, data, video, messaging, broadcast, and the like, to
multiple wireless users. The communications system 100 may enable
multiple wireless users to access such content through the sharing
of system resources, including wireless bandwidth. For example, the
communications systems 100 may employ one or more channel access
methods, such as code division multiple access (CDMA), time
division multiple access (TDMA), frequency division multiple access
(FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), and
the like.
As shown in FIG. 1A, the communications system 100 may include
wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a
radio access network (RAN) 104, a core network (CN) 106, a public
switched telephone network (PSTN) 108, the Internet 110, and other
networks 112, though it will be appreciated that the described
embodiments contemplate any number of WTRUs, base stations,
networks, and/or network elements. Each of the WTRUs 102a, 102b,
102c, 102d may be any type of device configured to operate and/or
communicate in a wireless environment. By way of example, the WTRUs
102a, 102b, 102c, 102d may be configured to transmit and/or receive
wireless signals and may include user equipment (UE), a mobile
station, a fixed or mobile subscriber unit, a pager, a cellular
telephone, a personal digital assistant (PDA), a smartphone, a
laptop, a notebook, a personal computer, a wireless sensor,
consumer electronics, and the like.
The communications systems 100 may also include a base station 114a
and a base station 114b. Each of the base stations 114a, 114b may
be any type of device configured to wirelessly interface with at
least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access
to one or more communication networks, such as the CN 106, the
Internet 110, and/or the other networks 112. By way of example, the
base stations 114a, 114b may be a base transceiver station (BTS), a
Node-B, an evolved Node-B (eNB), a Home Node-B (HNB), a Home eNB
(HeNB), a site controller, an access point (AP), a wireless router,
and the like. While the base stations 114a, 114b are each depicted
as a single element, it will be appreciated that the base stations
114a, 114b may include any number of interconnected base stations
and/or network elements.
The base station 114a may be part of the RAN 104, which may also
include other base stations and/or network elements (not shown),
such as a base station controller (BSC), a radio network controller
(RNC), relay nodes, and the like. The base station 114a and/or the
base station 114b may be configured to transmit and/or receive
wireless signals within a particular geographic region, which may
be referred to as a cell (not shown). The cell may further be
divided into cell sectors. For example, the cell associated with
the base station 114a may be divided into three sectors. Thus, in
one embodiment, the base station 114a may include three
transceivers, i.e., one for each sector of the cell. In another
embodiment, the base station 114a may employ multiple-input
multiple-output (MIMO) technology and, therefore, may utilize
multiple transceivers for each sector of the cell.
The base stations 114a, 114b may communicate with one or more of
the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which
may be any suitable wireless communication link, (e.g., radio
frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible
light, and the like). The air interface 116 may be established
using any suitable radio access technology (RAT).
More specifically, as noted above, the communications system 100
may be a multiple access system and may employ one or more channel
access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the
like. For example, the base station 114a in the RAN 104 and the
WTRUs 102a, 102b, 102c may implement a radio technology such as
universal mobile telecommunications system (UMTS) terrestrial radio
access (UTRA), which may establish the air interface 116 using
wideband CDMA (WCDMA). WCDMA may include communication protocols
such as high-speed packet access (HSPA) and/or evolved HSPA
(HSPA+). HSPA may include high-speed downlink (DL) packet access
(HSDPA) and/or high-speed uplink (UL) packet access (HSUPA).
In another embodiment, the base station 114a and the WTRUs 102a,
102b, 102c may implement a radio technology such as evolved UTRA
(E-UTRA), which may establish the air interface 116 using long term
evolution (LTE) and/or LTE-advanced (LTE-A).
In other embodiments, the base station 114a and the WTRUs 102a,
102b, 102c may implement radio technologies such as IEEE 802.16
(i.e., worldwide interoperability for microwave access (WiMAX)),
CDMA2000, CDMA2000 1.times., CDMA2000 evolution-data optimized
(EV-DO), Interim Standard 2000 (IS-2000), Interim Standard 95
(IS-95), Interim Standard 856 (IS-856), global system for mobile
communications (GSM), enhanced data rates for GSM evolution (EDGE),
GSM/EDGE RAN (GERAN), and the like.
The base station 114b in FIG. 1A may be a wireless router, HNB,
HeNB, or AP, for example, and may utilize any suitable RAT for
facilitating wireless connectivity in a localized area, such as a
place of business, a home, a vehicle, a campus, and the like. In
one embodiment, the base station 114b and the WTRUs 102c, 102d may
implement a radio technology such as IEEE 802.11 to establish a
wireless local area network (WLAN). In another embodiment, the base
station 114b and the WTRUs 102c, 102d may implement a radio
technology such as IEEE 802.15 to establish a wireless personal
area network (WPAN). In yet another embodiment, the base station
114b and the WTRUs 102c, 102d may utilize a cellular-based RAT,
(e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, and the like), to
establish a picocell or femtocell. As shown in FIG. 1A, the base
station 114b may have a direct connection to the Internet 110.
Thus, the base station 114b may not be required to access the
Internet 110 via the CN 106.
The RAN 104 may be in communication with the CN 106, which may be
any type of network configured to provide voice, data,
applications, and/or voice over Internet protocol (VoIP) services
to one or more of the WTRUs 102a, 102b, 102c, 102d. For example,
the CN 106 may provide call control, billing services, mobile
location-based services, pre-paid calling, Internet connectivity,
video distribution, and the like, and/or perform high-level
security functions, such as user authentication. Although not shown
in FIG. 1A, it will be appreciated that the RAN 104 and/or the CN
106 may be in direct or indirect communication with other RANs that
employ the same RAT as the RAN 104 or a different RAT. For example,
in addition to being connected to the RAN 104, which may be
utilizing an E-UTRA radio technology, the CN 106 may also be in
communication with another RAN (not shown) employing a GSM radio
technology.
The CN 106 may also serve as a gateway for the WTRUs 102a, 102b,
102c, 102d to access the PSTN 108, the Internet 110, and/or other
networks 112. The PSTN 108 may include circuit-switched telephone
networks that provide plain old telephone service (POTS). The
Internet 110 may include a global system of interconnected computer
networks and devices that use common communication protocols, such
as the transmission control protocol (TCP), user datagram protocol
(UDP) and the Internet protocol (IP) in the TCP/IP suite. The
networks 112 may include wired or wireless communications networks
owned and/or operated by other service providers. For example, the
networks 112 may include another CN connected to one or more RANs,
which may employ the same RAT as the RAN 104 or a different
RAT.
Some or all of the WTRUs 102a, 102b, 102c, 102d in the
communications system 100 may include multi-mode capabilities,
i.e., the WTRUs 102a, 102b, 102c, 102d may include multiple
transceivers for communicating with different wireless networks
over different wireless links. For example, the WTRU 102c shown in
FIG. 1A may be configured to communicate with the base station
114a, which may employ a cellular-based radio technology, and with
the base station 114b, which may employ an IEEE 802 radio
technology.
FIG. 1B shows an example WTRU 102 that may be used within the
communications system 100 shown in FIG. 1. As shown in FIG. 1B, the
WTRU 102 may include a processor 118, a transceiver 120, a
transmit/receive element, (e.g., an antenna), 122, a
speaker/microphone 124, a keypad. 126, a display/touchpad 128, a
non-removable memory 130, a removable memory 132, a power source
134, a global positioning system (GPS) chipset 136, and peripherals
138. It will be appreciated that the WTRU 102 may include any
sub-combination of the foregoing elements while remaining
consistent with an embodiment.
The processor 118 may be a general purpose processor, a special
purpose processor, a conventional processor, a digital signal
processor (DSP), a microprocessor, one or more microprocessors in
association with a DSP core, a controller, a microcontroller, an
application specific integrated circuit (ASIC), a field
programmable gate array (FPGA) circuit, an integrated circuit (IC),
a state machine, and the like. The processor 118 may perform signal
coding, data processing, power control, input/output processing,
and/or any other functionality that enables the WTRU 102 to operate
in a wireless environment. The processor 118 may be coupled to the
transceiver 120, which may be coupled to the transmit/receive
element 122. While FIG. 1B depicts the processor 118 and the
transceiver 120 as separate components, the processor 118 and the
transceiver 120 may be integrated together in an electronic package
or chip.
The transmit/receive element 122 may be configured to transmit
signals to, or receive signals from, a base station (e.g., the base
station 114a) over the air interface 116. For example, in one
embodiment, the transmit/receive element 122 may be an antenna
configured to transmit and/or receive RF signals. In another
embodiment, the transmit/receive element 122 may be an
emitter/detector configured to transmit and/or receive IR, UV, or
visible light signals, for example. In yet another embodiment, the
transmit/receive element 122 may be configured to transmit and
receive both RF and light signals. The transmit/receive element 122
may be configured to transmit and/or receive any combination of
wireless signals.
In addition, although the transmit/receive element 122 is depicted
in FIG. 1B as a single element, the WTRU 102 may include any number
of transmit/receive elements 122. More specifically, the WTRU 102
may employ MIMO technology. Thus, in one embodiment, the WTRU 102
may include two or more transmit/receive elements 122, (e.g.,
multiple antennas), for transmitting and receiving wireless signals
over the air interface 116.
The transceiver 120 may be configured to modulate the signals that
are to be transmitted by the transmit/receive element 122 and to
demodulate the signals that are received by the transmit/receive
element 122. As noted above, the WTRU 102 may have multi-mode
capabilities. Thus, the transceiver 120 may include multiple
transceivers for enabling the WTRU 102 to communicate via multiple
radio access technologies (RATs), such as UTRA and IEEE 802.11, for
example.
The processor 118 of the WTRU 102 may be coupled to, and may
receive user input data from, the speaker/microphone 124, the
keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal
display (LCD) display unit or organic light-emitting diode (OLED)
display unit). The processor 118 may also output user data to the
speaker/microphone 124, the keypad 126, and/or the display/touchpad
128. In addition, the processor 118 may access information from,
and store data in, any type of suitable memory, such as the
non-removable memory 130 and/or the removable memory 132. The
non-removable memory 130 may include random-access memory (RAM),
read-only memory (ROM), a hard disk, or any other type of memory
storage device. The removable memory 132 may include a subscriber
identity module (SIM) card, a memory stick, a secure digital (SD)
memory card, and the like. In other embodiments, the processor 118
may access information from, and store data in, memory that is not
physically located on the WTRU 102, such as on a server or a home
computer (not shown).
The processor 118 may receive power from the power source 134, and
may be configured to distribute and/or control the power to the
other components in the WTRU 102. The power source 134 may be any
suitable device for powering the WTRU 102. For example, the power
source 134 may include one or more dry cell batteries (e.g.,
nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride
(NiMH), lithium-ion (Li-ion), and the like), solar cells, fuel
cells, and the like.
The processor 118 may also be coupled to the GPS chipset 136, which
may be configured to provide location information (e.g., longitude
and latitude) regarding the current location of the WTRU 102. In
addition to, or in lieu of, the information from the GPS chipset
136, the WTRU 102 may receive location information over the air
interface 116 from a base station, (e.g., base stations 114a,
114b), and/or determine its location based on the timing of the
signals being received from two or more nearby base stations. The
WTRU 102 may acquire location information by way of any suitable
location-determination method while remaining consistent with an
embodiment.
The processor 118 may further be coupled to other peripherals 138,
which may include one or more software and/or hardware modules that
provide additional features, functionality and/or wired or wireless
connectivity. For example, the peripherals 138 may include an
accelerometer, an e-compass, a satellite transceiver, a digital
camera (for photographs or video), a universal serial bus (USB)
port, a vibration device, a television transceiver, a hands free
headset, a Bluetooth.RTM. module, a frequency modulated (FM) radio
unit, a digital music player, a media player, a video game player
module, an Internet browser, and the like.
FIG. 1C shows an example RAN 104 and an example CN 106 that may be
used within the communications system 100 shown in FIG. 1A. As
noted above, the RAN 104 may employ an E-UTRA radio technology to
communicate with the WTRUs 102a, 102b, 102c over the air interface
116. The RAN 104 may also be in communication with the CN 106.
The RAN 104 may include eNBs 140a, 140b, 140c, though it will be
appreciated that the RAN 104 may include any number of eNBs while
remaining consistent with an embodiment. The eNBs 140a, 140b, 140c
may each include one or more transceivers for communicating with
the WTRUs 102a, 102b, 102c over the air interface 116. In one
embodiment, the eNBs 140a, 140b, 140c may implement MIMO
technology. Thus, the eNB 140a, for example, may use multiple
antennas to transmit wireless signals to, and receive wireless
signals from, the WTRU 102a.
Each of the eNBs 140a, 140b, 140c may be associated with a
particular cell (not shown) and may be configured to handle radio
resource management decisions, handover decisions, scheduling of
users in the UL and/or DL, and the like. As shown in FIG. 1C, the
eNBs 140a, 140b, 140c may communicate with one another over an X2
interface.
The CN 106 shown in FIG. 1C may include a mobility management
entity (MME) 142, a serving gateway 144, and a packet data network
(PDN) gateway (GW) 146. While each of the foregoing elements is
depicted as part of the CN 106, it will be appreciated that any one
of these elements may be owned and/or operated by an entity other
than the CN operator.
The MME 142 may be connected to each of the eNBs 140a, 140b, 140c
in the RAN 104 via an S1 interface and may serve as a control node.
For example, the MME 142 may be responsible for authenticating
users of the WTRUs 102a, 102b, 102c, bearer
activation/deactivation, selecting a particular serving gateway
during an initial attach of the WTRUs 102a, 102b, 102c, and the
like. The MME 142 may also provide a control plane function for
switching between the RAN 104 and other RANs (not shown) that
employ other radio technologies, such as GSM or WCDMA.
The serving gateway 144 may be connected to each of the eNBs 140a,
140b, 140c in the RAN 104 via the S1 interface. The serving gateway
144 may generally route and forward user data packets to/from the
WTRUs 102a, 102b, 102c. The serving gateway 144 may also perform
other functions, such as anchoring user planes during inter-eNB
handovers, triggering paging when DL data is available for the
WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs
102a, 102b, 102c, and the like.
The serving gateway 144 may also be connected to the PDN gateway
146, which may provide the WTRUs 102a, 102b, 102c with access to
packet-switched networks, such as the Internet 110, to facilitate
communications between the WTRUs 102a, 102b, 102c and IP-enabled
devices.
The CN 106 may facilitate communications with other networks. For
example, the CN 106 may provide the WTRUs 102a, 102b, 102c with
access to circuit-switched networks, such as the PSTN 108, to
facilitate communications between the WTRUs 102a, 102b, 102c and
traditional land-line communications devices. For example, the CN
106 may include, or may communicate with, an IP gateway, (e.g., an
IP multimedia subsystem (IMS) server), that serves as an interface
between the CN 106 and the PSTN 108. In addition, the CN 106 may
provide the WTRUs 102a, 102b, 102c with access to other networks
112, which may include other wired or wireless networks that are
owned and/or operated by other service providers.
FIG. 2 shows the TV band spectrum usage. Analog TV bands 200
include the very high frequency (VHF) band and the ultra high
frequency (UHF) band. The VHF band is composed of a low VHF band
205 operating from 54 MHz to 88 MHz, (excluding 72 MHz to 76 MHz),
and a high VHF band 210 operating from 174 MHz to 216 MHz. The UHF
band is composed of a low UHF band 215 operating from 470 MHz to
698 MHz, and a high. UHF band 220 operating from 698 MHz to 806
MHz.
In the United States, the Federal Communications Commission (FCC)
set Jun. 12, 2009 as the deadline for replacing analog TV
broadcasting with digital TV broadcasting. The digital TV channel
definitions are the same as the analog TV channel. The digital TV
bands 225 may use analog TV channels 2 to 51 (except 37), while the
analog TV channels 52 to 69 may be used for new non-broadcast
users.
The frequency allocated to a broadcasting service, but not used
locally, is called white space (WS). Television WS (TVWS) refers to
TV channels 2 to 51, (except 37).
Besides TV signals, there are other licensed signals transmitted on
the TV bands. The starting frequency of frequency modulation (FM)
channel 227 is 87.9 MHz, which partial overlaps TV channel 6.
Channel 37 is reserved for radio astronomy 230 and wireless medical
telemetry service (WMTS) 235, where the latter may operate on any
vacant TV channels 7 to 46. The private land mobile radio system
(PLMRS) 240 uses channels 14 to 20 in certain metropolitan areas.
Remote control devices 245 may use any channels above channel 4,
except channel 37. The wireless microphone 250 uses channels 2 to
51 with a bandwidth of 200 kHz.
Furthermore, the FCC allows unlicensed radio transmitters to
operate on the TVWS except channels 3, 4 and 37, as long as minimum
interference is caused to the licensed radio transmissions. Hence,
the operation of unlicensed radio transmitters may have to satisfy
several restrictions. There are three kinds of unlicensed TV band
devices (TVBDs): a fixed TVBD 255, a mode I portable (or personal)
TVBD 260, and a mode II portable (or personal) TVBD 265. Both fixed
TVBDs 255 and mode II portable TVBDs 265 may have a
geo-location/database access capability and register to a TV band
database. Access to the TV band database is used to query the
allowed TV channels, so as to avoid the interference with digital
TV signals and licensed signals transmitted on the TV bands.
Spectrum sensing is considered as an add-on feature for TVBDs to
minimize interference caused to digital TV signals and licensed
signals. Furthermore, a sensing-only TVBD may be allowed to operate
on TVWS if its access to a TV band database is limited.
Fixed TVBD 255 may operate on channels 2 to 51, except channels 3,
4, 37, but it cannot operate on the same or the first adjacent
channel to a channel used by TV services. The maximum transmission
power of fixed TVBD 255 is 1 W, with at most 6 dBi antenna gain.
Hence, the maximum effective isotropic radiated power (EIRP) is
limited to 4 W. Portable TVBDs 260 and 265 can operate on channels
21 to 51, except channel 37, but it cannot operate on the same
channel used by TV services. The maximum transmission power of
portable TVBDs 260 and 265 are 100 mW or 40 mW, if it is on the
first adjacent channel to a channel used by TV services.
Furthermore, if a TVBD device is a sensing-only device, then its
transmission power cannot exceed 50 mW. All the TVBDs have strict
out-of-band emissions. The antenna (outdoor) height of fixed TVBD
must be less than 30 meters, while there is no limitation on the
antenna height for portable TVBD.
A cell is typically controlled by a single base station. In LTE, a
primary cell may refer to the cell which a given WTRU camps and
uses for most of its mobility related procedures. The primary cell
may include, but is not limited to, an uplink component carrier (UL
CC) and a downlink component carrier (DL CC) or solely to a DL CC.
When a cell is aggregated with a primary cell, the aggregated cell
may be referred to as a secondary cell. Although the description
herein below is in terms of the primary cell, a secondary cell may
also used in place of the primary cell.
As described herein, the term supplementary cell may refer to
enhanced operations in an LE spectrum. The supplementary cell may
refer to a cell operating in LE spectrum or bands in conjunction
with primary and secondary cells, (where the term aggregating cell
may refer to a primary cell, a secondary cell or both). The
supplementary cell may be DL only, UL only or time division duplex
(TDD) UL/DL. The supplementary cell may include a DL supplementary
CC (DL SuppCC), an UL SuppCC or both. Although the description
herein may refer to SuppCCs, it is also applicable to supplementary
cells.
SuppCCs may be deployed in an opportunistic fashion to make use of
LE spectrum including but not limited to TVWS, industrial,
scientific and medical (ISM), sublicensed, or opportunistic bands
or spectrum. In an embodiment, heterogeneous network deployments
make use of advanced LE carrier aggregation (CA) methods, systems
and devices to provide hot-spot overage.
FIG. 3 shows an example of LE CA deployment. A heterogeneous
network architecture 300 may include a core network 302, an LTE
macro cell 305 and an underlay of pico cells 308, femto cells 310
and remote radio head (RRH) cells 315 that may aggregate licensed
and LE bands. Macro cells 305 may provide service continuity, and
pico cells 308 and femto cells 310 may provide hot-spot coverage. A
coexistence database 320 along with new mechanisms such as
coexistence gaps may be implemented to coordinate operation with
other secondary networks and users operating in LE bands. A TVWS
database 325 may be used to protect incumbent users operating in
the TVWS band. Infrastructure to support dynamic spectrum trading
may be implemented across both licensed and LE bands. LE bands may
be used by both HeNB deployments or RRH/pico cell campus type
deployments.
Described herein below are embodiments and examples of systems and
methods for aggregation over LE bands. In an embodiment aggregation
over LE bands may be performed by implementing a system which
aggregates licensed carriers/cells (using LTE frequency division
duplex (FDD)) with one or more SuppCCs), using a time division
duplex (TDD) configuration that may be dynamically changed by the
pico/femto cell, (which may be referred to herein as enhanced TDD).
In another embodiment, a dynamically changed enhanced TDD
configuration may be implemented to alter the duration of a guard
period between uplink (UL)/downlink (DL) transitions based on the
frequency of operation of a SuppCC.
An enhanced TDD operation may be implemented in another embodiment
where hybrid automatic repeat request (HARQ) feedback timing for
the SuppCC may be based on the "n+/4" timing used for the primary
cell. The primary cell may be used to carry HARQ feedback for the
DL and UL transmissions on the SuppCC, as well as the channel state
information (CSI) for the SuppCCs. An enhanced TDD operation may be
implemented in another embodiment where timing for UL grants for
the SuppCC is based on "n+4" timing. That is, current sub-frame "n"
carries UL scheduling/grant for sub-frame "n+4". The grant
information may be carried on the SuppCC or it may be carried on
the primary CC (PCC), (e.g., relying on cross-carrier
scheduling).
Another system embodiment may be implemented which aggregates
licensed carriers, (using LTE FDD), with one or more SuppCCs, and
where these SuppCCs may dynamically change from being configured as
UL only, DL only, or shared, (quick toggling of sub-frames from UL
to DL and vice versa). A shared mode aggregation embodiment may be
implemented where the SuppCC may rely on the primary cell CCs for
sub-frame timing.
Another shared mode aggregation embodiment may be implemented which
provides for flexible UL/DL ratios resulting in optimum DL:UL
sub-frame patterns. The pattern may be based on a repeat-K
structure, with N DL sub-frames followed by M UL sub-frames N+M=K.
HARQ feedback may be bundled to compensate for UL/DL asymmetry.
Downlink control information (DCI) may carry an indication as to
the sub-frame where the information is applicable. HARQ
round-trip-time (RTT) may be variable and depend on the sub-frame
used for the prior transmission. The HARQ feedback may be sent on
the primary cell CC or the SuppCC based on the sub-frame used for
the prior transmissions.
Based on the need to operate both UL and DL resources in the same
LE channel, the general approach for the embodiments described
herein is to use an FDD licensed spectrum as a primary cell which
provides both UL and DL primary component carries (PCCs), and to
dynamically aggregate a supplementary LE carrier in either the UL
or DL for a given time interval. This ensures that the radio
operating in the LE spectrum does not need to transmit or receive
in the LE band simultaneously.
FIG. 4 shows an example of a supplementary LE carrier aggregated
with an LTE primary cell. The LTE primary cell may include an UL CC
and a DL CC, or a DL CC only. In particular, the LTE primary cell
may include an FDD DL primary carrier 405 operating on a DL FDD
licensed band 410 and an FDD UL primary carrier 415 operating on an
UL FDD licensed band 420, which are carrier aggregated with an
UL/DL SuppCC 425 operating in a LE band 430 for example, TVWS or
ISM bands. The UL/DL SuppCC may alternate between DL operation in
one time interval 435, UL operation in another time interval 440,
DL operation in another time interval 445 and so on.
Although the embodiments show a single SuppCC, it should be
understood that the embodiments presented can be extended to cases
with multiple SuppCCs. In all cases, the SuppCCs may be treated as
additional bandwidth to be used for communication to/from
LE-capable WTRUs. All decisions regarding the activation,
deactivation, and (re)configuration of SuppCCs may be driven by
algorithms, processes and methods running in a radio resource
management (RRM) functionality.
The RRM may provide an indication of the ratio of UL and DL
resources required for the SuppCC(s), depending on observed system
conditions. The RRM may attempt to resolve UL congestion if this
ratio is skewed to the UL side. DL congestion if this ratio is
skewed to the DL side, or system-wide congestion, (increasing the
capacity available on both the UL and DL), if the ratio is almost
symmetric.
The RRM may provide some indication as to how long the
supplementary cell may be used with this ratio, or additional
information, (potentially providing constraints), on use of the
supplementary cell.
Described herein are two embodiments that illustrate SuppCC
realizations. In the first embodiment, the FDD primary cell is
aggregated with a dynamic FDD SuppCC and in the second embodiment,
the FDD primary cell is aggregated with an TDD SuppCC.
Described initially are system considerations applicable to both
embodiments. A system embodiment may require a coexistence
capability so that the LTE system may coexist with other systems
operating in an LE spectrum. Such coexistence may be coordinated,
(via direct and/or indirect communication), or non-coordinated
between the different systems, (the term coexistence does not
presume fair usage of the spectrum). The LTE system may be able to
operate even in the presence of other systems operating in LE
spectrum. The LTE system may coexist with systems using LTE as well
as other RATs. In addition, heterogeneous coexistence with a WiFi
system may be supported. In a coordinated single RAT scenario,
coexistence may allow for co-channel sharing. In non-coordinated
scenarios, coexistence may rely on lower layer mechanisms, such as
coexistence gaps or other interference mitigation algorithms.
Supplementary cell operation may adapt to different types of TVWS
channels and other LE bands. For example, one type may be
sublicensed channels. A sublicensed channel may be a TVWS channel
that is sublicensed to an operator or user for a specific
geographical area and for a specific time which is not used by any
primary user and other secondary users, (i.e., typically a channel
originally owned by a digital television (DTV) broadcast station
but was made available through an agreement and/or brokerage).
Another example may be an available channel type. This type may
include an available TVWS channel that is not occupied by a primary
user (PU) but may be used by any secondary users (SU). Another
example may be a PU assigned channel type. This type may be an
assigned TVWS channel that is used by a PU which may require SUs to
leave the channel if a PU is detected.
FIG. 5 shows an example of a high level advanced LTE spectrum
solution (ALTESS) in a system 500 including a WTRU 505, an HeNB
510, an HeNB management system (HeMS) 515, an inter-operator
coexistence manager (CM) function 520, a TVWS database 525, a
coexistence discovery and information server (CDIS) 530, a serving
gateway (SGW) 535 and a mobility management entity (MME) 540.
The HeNB 510 may include a physical (PHY) layer 542, a medium
access control (MAC) layer 544, a radio link control (RLC) layer
546, a packet data convergence protocol (PDCP) layer 547, a radio
resource control (RRC) layer 548, a sensing toolbox 550 and an HeNB
dynamic spectrum management (DSM) radio resource management (RRM)
entity 552. The HeNB 510 may be enhanced to support operation in
TVWS and other LE bands. Functions in the different LTE layers of
the HeNB 510, (a PHY layer 542, a MAC layer 544, an RLC layer 546
and an RRC layer 548), may be enhanced to support the operation in
the TVWS and other LE spectrum by new mechanisms and/or hooks. For
example, the PHY layer 542 may be modified to support operation of
the aggregated CCs in an LE band with no fixed frequency duplex
separation, and enhance feedback channels in LTE to support UL or
DL only CCs, or other enhancements to support UL "heavy"
configurations or optimize HARQ performance. The PHY layer 542 and
the RRC layer 548 may be modified to reduce the overhead associated
with carrying unnecessary control channel information. The MAC
layer 544 and the PHY layer 542 may be modified to introduce a
coexistence gap in LTE transmissions to allow access to other
secondary users. The RRC layer 548 may be modified to support
enhancement for measurements and to detect primary users. The RRC
layer 548 may be modified to support new triggering mechanisms to
transition into the different new modes of operation in FDD frame
structure solutions. The MAC layer 544 and the RLC layer 546 may be
modified to handle DL/UL transition, especially for HARQ
buffers.
A sensing toolbox 550 may be integrated in the HeNB 510 for
performing and processing cognitive sensing on the LE spectrum and
reporting the results to the HeNB DSM RRM entity 552. The HeNB DSM
RRM entity 552 may be an enhancement of an existing HeNB RRM by
ALTESS features related to the TVWS spectrum management and
operation. Also it may control/configure the sensing toolbox
operation. As described herein below, RRM functions may be required
to support channel allocation algorithms that may quickly adapt to
temporal variations in channel availability and quality. The HeNB
510 may also include a coexistence enabler function which acts as
an interface between the CM 520 and the cognitive networks, for
example white space radio systems or TVBD networks. Its functional
roles are translating reconfiguration commands received from the CM
520 into network-specific reconfiguration commands and sending them
to the cognitive network, so that the later can reconfigure
itself.
The WTRU 505 may include a PHY layer 554, a MAC layer 556, an RLC
layer 558, a packet data convergence protocol (PDCP) layer 559, an
RRC layer 560, a sensing toolbox 562, a WTRU DSM RRM entity 564 and
a non-access stratum (NAS) layer 566. The WTRU 505 may be enhanced
to support TVWS and LE operation.
Functions in the different LTE layers of the WTRU 505, (PHY layer
554, MAC layer 556, RLC layer 558 and RRC layer 560), may be
enhanced to support the operation in the TVWS and other LE spectrum
by new mechanisms and/or hooks. These may be the client side of the
enhancements required as previously described for the HeNB 510.
A sensing toolbox 562 may be integrated in the WTRU 505. It is
responsible for performing and processing cognitive sensing on the
TVWS and other LE spectrum and report the results to the WTRU DSM
RRM entity 564 and supporting measurement gaps for
primary/secondary user detection. WTRUs supporting this capability
may benefit from having access to a broader set of TVWS CCs. The
WTRU DSM RRM entity 564 may be an enhancement of the existing WTRU
RRM to support the HeNB DSM RRM entity 552 operation as well as to
control and configure the operation of the sensing toolbox 562
operation.
The HeMS 515 is a third generation partnership project (3GPP) LTE
operations, administration and maintenance (OAM) entity that may
configure multiple HeNBs. The HeMS 515 may be able to reboot the
HeNB 510, setup the operating frequencies in the licensed bands, as
well as PHY/MAC parameters, command the start stop transmissions on
certain frequencies and download software to the HeNB 510.
The HeMS 515 may include a coexistence manager (CM) entity 570, an
operator's coexistence database 572 and policies 574. The CM entity
570 may be responsible for managing inter-HeNBs as well as an
inter-operator coexistence operation. For example, the GM entity
570, based on information received from the TVWS database 525, the
CDIS 530 and sensing and usage data may process the initial list of
available channels from the TVWS database 525 and provide channel
usage information to the inquiring HeNB, which may include a
processed list of candidate channels and additional information
from which the HeNB may select the channel(s). The sensing and
usage data may originate from the HeNBs under its supervision, as
well as information from neighbor networks (inter-operator), and
may be stored in the operator's coexistence database 572. The CM
entity 570 may be connected to a third party that provides a TVWS
channel brokerage service.
The CM entity 570 may maintain the operator coexistence database
572, update the CDIS 530 and the TVWS database 525 about the
networks within the operator's control, acquire sensing and usage
data including information from neighboring CM functions, and
construct and maintain an interdependency mapping for each HeNB
under its supervision to identify HeNBs and access points (APs) of
the operator's network as well as other networks registered in the
CDIS potentially interfering or impacted by the given HeNB.
The CM entity 570 may process and forward the TVWS channel usage
information to requesting HeNBs which may include some initial
ranking of the available channels as well as proposing
non-conflicting physical cell identifiers (IDs) for each channel
frequency.
The operator's coexistence database 572 may contain the TVWS usage
information (i.e., sensing and usage data) of all networks
operating in that band which may impact the operator's own network.
The operator's coexistence database 572 may reside in the HeMS 515
next to the CM entity 570 and may contain a number of entries, each
one corresponding to one HeNB entity or AP operating on TVWS
bands.
An interface 576, (i.e., OAM "interface type 1"), may be used to
exchange coexistence information between the HeNB 510 and the HeMS
515, as well as perform existing management functions as described
below. It may also be used to transfer policies 574 between the
HeMS 515 and the HeNB 510. The interface 576 may instruct use of a
management protocol, for example a TR-069 management protocol,
which supports a variety of functionalities allowing the HeMS 515
to manage multiple HeNBs including the following primary
capabilities: auto-configuration and dynamic service provisioning,
software/firmware image download and management, status and
performance monitoring, and diagnostic. A data model for a femto
cell for remote management may use the TR-069 management
protocol.
The TVWS database 525 may be a geo-location database map of
reserved TVWS channels for microphone and DTV signals complying to
FCC regulations. Mode II or fixed TVWS devices may query directly
or indirectly the TVWS database 525 by indicating their
geo-location to obtain access to an available channel. In this
architecture, the CM entity 570 may query the TVWS database 525 on
behalf of the HeNB 510 to obtain a list of available channels.
The CDIS 530 may provide neighbor discovery service to CM entities.
Based on the location provided, the CDIS 530 may respond with a
list of CMs under which networks are operating at that specific
location, as well as the contact information of those networks.
TVWS usage information of secondary networks may be stored in the
CDIS 530. However, this information may be distributed in the
operator's coexistence database 572.
The SGW 535 may be configured to perform packet routing and
forwarding, lawful interception, transport level packet marking in
the UL and DL, charging per WTRU, packet data network (PDN) and
quality of service (QoS) class identifier (QCI), and mobility
anchoring.
The MME 540 may be configured to perform NAS signaling, NAS
signaling security, access stratum (AS) security control, idle mode
WTRU reachability, tracking area list management, PDN and SGW
selection, authentication, roaming and bearer management
functions.
Described herein is supplementary or supplemental cell operation.
As described herein above, the supplementary cell is a cell
operating in LE spectrum or bands, for example TVWS and/or ISM
bands, in conjunction with primary and secondary cells. The
supplementary cell may not operate as a standalone cell. WTRUs may
not select supplementary cells in idle mode. Supplementary cells
may be used to aggregate additional CCs to a primary cell. System
information block (SIB) information associated with the
supplementary cell may not be broadcast, and WTRUs operating under
this supplementary cell may be signaled associated SIB information
through dedicated signaling.
LE bands, such as the TVWS band, may not have a predetermined fixed
frequency duplex separation which may make it difficult to
arbitrarily define a fixed frequency duplex separation between DL
and UL transmission. Furthermore, it may be possible that only one
supplementary CC may be available at a given time. Therefore, the
supplementary cells active in a given band may operate in TDD
fashion. In one embodiment, supplementary cell aggregation using
CCs may be based on an existing TDD frame structure. In another
embodiment, supplementary cell aggregation using CCs may be based
on the existing FDD frame structure. In the latter case, the HeNB
may dynamically change the supplementary CCs to operate in the DL
or the UL. In the case of heavy UL traffic demand, the
supplementary cell will operate in UL only for a long period of
time until UL congestion is mitigated. For example, if UL traffic
congestion is detected, the supplementary cell currently operating
in DL may switch to operate in UL only operation until UL
congestion is mitigated. Furthermore, both embodiments may be
simplified or enhanced, as supplementary cells may rely on the
capability of the primary cell to carry control and feedback
information.
The supplementary cell may require the introduction of coexistence
gaps to free up the medium and thus enable other wireless networks
to gain access to the medium. During these gaps, new measurements
may be taken to assess usage of both primary and secondary users. A
listen-before-talk mechanism may be introduced at the end of the
coexistence gaps.
Supplementary cells may be non-Release 8 (R8) backward compatible,
which may allow certain information overhead to be removed. Likely
resources that may be released are the master information block
(MIB), SIB and a portion of the physical DL control channel (PDCCH)
in the DL. In the UL, resources associated with the random access
channel (RACH) and the physical UL control channel (PUCCH) may also
be released. A primary shared channel (SCH) and a secondary SCH may
remain for frequency synchronization and cell search purposes.
The supplementary cells may not be as static as secondary cells as
the HeNB may have to frequently stop operation on a given
supplementary cell due to high level interference, the arrival of
primary users or coexistence database decisions, and the like.
Active supplementary cells may have to operate in the presence of a
higher level of interference than what is typically present in the
licensed spectrum, and may include new types of interferers, such
as WiFi, Bluetooth.RTM. and even non-communication interferers such
as microwave ovens. Therefore, critical control information such as
the PDCCH, reference symbols, and the like, may be required to be
sent in a more robust way.
Described herein is an FDD primary cell aggregating a dynamic FDD
SuppCC. In particular, an FDD carrier, (operating in a licensed
spectrum), aggregates a dynamic FDD supplementary carrier,
(operating in a LE spectrum), using the existing FDD frame
structure and which may dynamically change the SuppCC to aggregate
in the DL or the UL. The CCs may be configured to address the
required ratio of UL and DL resources or traffic, and can be in one
of three operating modes: DL only, UL only, and shared.
FIG. 6 shows an example of dynamic FDD operating modes. A cell 600
may include a primary DL CC 605 operating in a licensed band and a
primary UL CC 610 operating in a licensed band. Also shown are
three supplementary cell CCs 615, 620 and 625 using dynamic FDD.
Each of the supplementary cells may transition between the three
operating modes. In one example, the supplementary cells may
transition independently from each other. For example,
supplementary cell 615 may transition from a DL only mode 630, to
an UL only mode 632, back to another DL only mode 634 and then to a
shared mode 636. In this embodiment, supplementary cell may be
activated and deactivated as needed. For example, supplementary
cell 2 620 is deactivated between times T1 and T3 640.
The SuppCCs may not necessarily be the same size as the licensed
band carriers. For example, the three SuppCCs 615, 620 and 625 may
be 5 MHz SuppCCs in aggregation with a 10 MHz primary FDD cell,
(which may include both an UL and DL CC). If more than one SuppCC
is configured, the operating mode may be the same across all
activated SuppCCs. This may be performed to reduce the
implementation complexity at the WTRUs. In the embodiment shown,
all SuppCCs are operating in DL only mode between times T3 and
T4.
In one example, the SuppCCs may be in a DL-only mode, characterized
by a desired DL:UL ratio heavily skewed on the DL. This mode may be
used to relieve DL congestion. The cell may schedule DL
transmissions on these DL SuppCCs to all capable WTRUs.
In another example, the SuppCCs may be in an UL-only mode,
characterized by a desired DL:UL ratio heavily skewed on the UL.
This mode may be used to relieve UL congestion. The cell may
schedule UL transmissions on these UL SuppCCs to all capable
WTRUs.
In another example, the SuppCCs may be in a shared mode,
characterized by carriers which may quickly toggle between the UL
and the DL. For example, the toggling interval may be of an order
of several sub-frames. In particular, over a period K+L sub-frames,
the SuppCCs may be used for DL transmissions in K sub-frames and
for UL transmissions in L sub-frames, K and L are chosen to match
the requested DL:UL ratio (DL:UL.about.K/(K+L):L/(K+L)). For
example, supplementary cell 3 625 shows a 50%:50% DL/UL ratio, with
the supplementary cell CC toggling every several sub-frames
645.
In addition, although FIG. 6 shows only a primary serving cell and
a number of supplementary cells, it should be understood that the
aggregation may extend over a number of secondary serving
cells.
If required, an LTE system may operate a SuppCC on a single
operating mode, (deactivating the SuppCC when no longer needed).
Alternatively, the LTE system may dynamically change from one
operating mode to another.
The DL-only operating mode may be characterized by the primary CCs
(UL and DL) aggregated with one or more DL SuppCCs. The cell may
uses the SuppCCs as additional bandwidth on which it may schedule
DL transmissions. FIG. 7 shows example solutions for different
procedures impacting SuppCCs in a DL-only operating mode.
The UL-only operating mode may be characterized by the primary CCs
(UL and DL) aggregated with one or more UL SuppCCs. The cell uses
the SuppCCs as additional bandwidth on which it may grant UL
capacity to a WTRU. FIG. 8 shows example solutions for different
procedures impacting SuppCCs in an UL-only operating mode.
In a shared operating mode, the pico/femto cell may determine the
best pattern to match the requested DL:UL ratio requested from the
RRM functionality. The pico/femto cell may determine this
dynamically, (e.g., based on some formulas, or it may have a
preconfigured set). When determining the optimum pattern, the
pico/femto cell may rely on a number of guiding principles
including, for example, minimizing the number of UL to DL
transitions and DL UL transitions, or minimizing the effect on
hybrid automatic repeat request (HARQ) procedures that deal with
positive acknowledgement (ACK)/negative acknowledgement (NACK)
transmission and HARQ retransmissions.
The SuppCC using a shared operating mode may rely only on sub-frame
timing, which may be derived from the PCC. The DL sub-frames may be
time aligned with the DL sub frames on the DL PCC.
FIG. 9 shows an example of timing alignment for a 4DL-4UL related
pattern. A cell 900 may include a DL FCC 905 and an UL PCC 910. The
cell 900 may be aggregated with a SuppCC 915. In this embodiment,
while the UL sub-frames 920 are time aligned with the UL PCC
sub-frames 925, the UL sub-frames 920 may be time-advanced to
reduce the potential interference with the DL sub-frame
transmissions 930. This timing advancement may be tied to that of
the PCC.
At the DL-UL transition 935, the DL sub-frame 940 may be a special
sub-frame that is only partially used for data transmission. The
rest of the sub-frame 940 may be a guard (gap) period 945 which may
be used to allow the WTRU to transition from reception to
transmission mode. Although the system may be flexible to support
any DL:UL pattern, the pattern may repeat every K sub-frames,
(hereafter referred to as a repeat K pattern), when K is a multiple
of the number of HARQ processes used in the primary cell, (8 for an
FDD LTE system). In such a case, the WTRU and the pico/femto cell
may use modified HARQ and retransmission rules to send ACK/NACK
feedback, as well as retransmissions, (e.g., as a result of a NACK
reception).
For a repeat-8 pattern, the retransmissions may occur exactly a
number (n+8) of scab-frames after the previous transmission. The
HARQ feedback may be carried either on the primary cell, or it may
be carried in the SuppCC. For the latter case, (use of SuppCC), the
feedback may be bundled to deal with the UL/DL asymmetry.
FIGS. 10A and 10B show examples of HARQ details for repeat-8
patterns, (a primary cell with an HARQ round-trip-time (RTT) of 8
sub-frames). FIG. 10A shows an example for DL:DL pattern of 4:4 and
FIG. 10B shows an example for DL:DL pattern of 2:6. Although FIGS.
10A and 10B are discussed with respect to a primary cell, it is
applicable to supplementary cells. In general, for the 4:4 pattern
1000, each DL subframe 1002, 1004, 1006, and 1008 may carry
feedback for an UL subframe 1003, 1005, 1007 and 1009,
respectively. This is also applicable for UL subframes carrying
feedback information for DL subframes. Although FIGS. 10A and 10B
are discussed with respect to a primary cell, it is applicable to
supplementary cells as appropriate.
For the 2:6 pattern 1020, the feedback for the DL transmissions do
not need to be bundled. However, the 2 DL sub-frames 1025 and 1030,
(in each set of 8 sub-frames), need to carry feedback for 3 UL
subframes 1035 and 1040, respectively. The UL HARQ feedback may be
carried in a feedback channel, (e.g., a modified physical HARQ
indicator channel (PHICH) for LTE), or in a new feedback channel
visible to only WTRUs capable of carrier aggregation over LE bands.
In the 2:6 pattern 1020, UL subframes 1045 and 1050 may carry
feedback for DL subframes 1055 and 1060, respectively.
For the repeat-8 patterns, the DL control signaling, (DL scheduling
and UL grants), may be carried on the primary cell relying on the
timing rules for the primary cell and cross carrier scheduling. As
shown in FIG. 10A for the 4:4 pattern, the DL scheduling
information for frame "n" may be carried in frame "n". UL grants
carried in frame n may be used to schedule future transmissions in
frame "n+k", where k depends on the repeat-8 pattern. The value of
k may be signaled with the grant, or derived implicitly, (e.g.,
based on a specific WTRU address for example a radio network
temporary identity (RNTI), where k refers to grant for UL sub-frame
k).
Alternatively, the DL control information may be carried on the DL
sub-frames using a form of bundled grant. In this case, the DL
sub-frames may have to provide UL grants for more than one UL
sub-frame. As shown in FIG. 10B for the 2DL:6UL pattern, a DL
sub-frame, for example subframe D1, may provide UL grants for 3 UL
sub-frames, for example sub-frames U1, U3 and U5. This asymmetric
pattern may require additional processing. For example, in 3rd
Generation Partnership Project (3GPP) Release 10, the UL grant may
contain an identity of the WTRU to whom the grant applies. For
asymmetric shared mode operation, the UL grant may also have to
contain an indication of the time at which this grant applies, (the
grant received in frame n applies to UL sub-frame n+k). The value
of k may be explicitly included in the grant information, (e.g.
grant applies to WTRU 1 in sub-frame n+6). Alternatively, the value
of k may be determined implicitly. For instance, a WTRU could be
assigned 3 addresses, (radio network temporary identifier (RNTI_2),
RNTI_4, and RNTI_6). Receiving an UL grant for RNTI_6 implies that
the grant applies to this WTRU in frame n.+-.6.
FIGS. 11A and 11B show examples of HARQ details for a repeat-16
pattern, (a primary cell with an HARQ RTT of 16 sub-frames). For a
repeat-16 pattern, the retransmission schedule may be based on the
sub-frame used for the initial transmission. FIG. 11A shows an
example of a DL:UL 4:12 pattern 1100, where the HARQ feedback is
carried on the SuppCC using bundled HARQs 1105, 1110, 1115 and
1120, for example. The HARQ RTT is 16 sub-frames and would require
an increase in the maximum number of HARQ processes. For example,
the number of HARQ processes in the UL may be 12.
FIG. 11B illustrates an alternative feedback mechanism for DL:UL
4:12 pattern 1125, where all or part of the HARQ feedback may be
carried in the primary cell. The feedback for UL sub-frames U1, U2,
U3, and U4 are carried on the primary cell 1130. For example, the
acknowledgement (ACK)/negative ACK (NACK) for the packet sent in
the UL at subframe U1 is sent by the base station over the primary
cell on the DL CC using the PHICH 4 subframes after transmission of
the packet. The feedback for UL sub-frames U5-U12 may be carried in
the SuppCC 1140. For feedback carried on the primary cell, the FDD
LTE "n+4" timing rules may be used. If the primary cell is used to
carry feedback, it is possible to maintain the number of HARQ
processes to 8. For this alternative approach, the WTRU and
pico/femto cell may be aware of the HARQ RTT for each of the
sub-frames, as well as where the feedback is being transmitted. For
DL sub-frames 1-4, the RTT is 16 sub-frames. For UL sub-frames 1-4,
the RTT is 8 sub-frames. For UL sub-frames 5-12, the RTT is 12
sub-frames.
Described herein are embodiments for dynamic control of the SuppCC.
In one embodiment, the direction of the aggregation may be
dynamically changed through an RRC reconfiguration sent over the
primary carrier. FIG. 12 shows a cell 1200 that may include an FDD
UL primary carrier 1205 operating in a DL FDD licensed band and an
FDD UL primary carrier 1210 operating in an UL FDD licensed band.
The cell 1200 is aggregated with a SuppCC 1215 operating in a LE
band such as a TVWS or ISM band. Initially, the aggregation
direction is in the UL direction 1220. A RRC Reconfiguration
message 1225 is received. In general, LTE delivers and processes
RRC messages within 15 ms in connected mode. The aggregation
direction is then changed to the DL direction 1230.
In another embodiment, the direction of the aggregation may also be
dynamically changed through a medium access control (MAC) control
element (CE) command sent over the primary carrier. FIG. 13 shows a
cell 1300 that may include an FDD DL primary carrier 1305 operating
in a DL FDD licensed band and an FDD UL primary carrier 1310
operating in an UL FDD licensed band. The cell 1300 is aggregated
with a SuppCC 1315 operating in a LE band such as a TVWS or ISM
band. RRC reconfiguration messages 1320 may have preconfigured both
UL and DL SuppCCs in the LE spectrum. Initially, the SuppCC 1315
may have aggregation activated in one direction 1322. A MAC CE
message 1325 may subsequently activate a SuppCC 1315 aggregation in
another direction 1330 and deactivate the SuppCC aggregation in the
other direction 1322.
A new MAC scheduler and buffering scheme may be used to retain
temporarily deactivated UL or DL MAC protocol data units (MPDUs)
when switching the SuppCC from DL to UL, or vice versa. Note that
both FDD carriers make aggregation synchronous and additional
memory may not be required.
In addition, new guard periods (GPs) may be added for dynamic FDD
prior to any transition of the SuppCC from DL to UL, or vice versa.
This may apply also for any transitions from one operating mode to
another, (e.g., from the DL-only operating mode to the UL-only
operating mode). This guard period may be configured based on the
range or size of the cell. It may also be changed/reconfigured
dynamically via RRC reconfiguration messages.
PHICH may be transmitted on the DL carrier that was used to
transmit the UL grant. The timing of responses to be expected on
the PHICH may differ in FDD and TDD. For FDD, DL ACK/NACK may be
sent 4 subframes after the UL transmission, but in TDD this may be
variable. The mapping of PHICH resources may also differ. In FDD,
all frames may have the same number of PHICH resource elements in
the first orthogonal frequency division multiplexing (OFDM) symbol.
In TDD, the number of PHICH resource elements may depend on the
subframe. In TDD, the size of the PHICH may be adjusted based on
the UL/UL configuration, (an UL-heavy configuration may have more
resource elements allocated to the PHICH). PHICH collisions may be
considered for the case of cross-carrier scheduling, (resolved by a
demodulation reference signal (DMRS) cyclic shift mechanism).
Therefore, if an FDD carrier is used in white space, this could
result in an UL heavy configuration with a potential for PHICH
collisions. One possibility is to define an additional PHICH
allocation which may be sent over the RRC reconfiguration message
while configuring the SuppCC. These PHICH configurations may be
changed when the SuppCC is reconfigured from UL to DL in order to
adapt to the load, (either UL heavy or DL heavy), of the channel.
The PDCCH in the licensed band, (allocation and configuration), may
then be modified based on the new PHICH allocations that occur in
the first OFDM symbol of each subframe.
When the unlicensed band carrier is set to DL only, the unlicensed
band UL control information like channel quality indication
(CQI/precoding matrix information (PMI)/rank indication (RI),
ACK/NACK/discontinuous transmission (DTX) may be sent over the
primary carrier FDD UL. The format of the control information will
include corresponding bit fields on FDD UL for that purpose.
Described herein is an FDD primary cell aggregating an TDD SuppCC
In particular, a primary FDD carrier operating in a licensed band
aggregates with a SuppCC operating in a LE band based on an
existing LTE-TDD frame. Multiple UL and DL supplementary
transmission opportunities may exist in each frame, depending on
asymmetry configuration.
FIG. 14 shows an example of a licensed band FDD primary cell 1400
containing an UL CC 1405 and a DL CC 1410 aggregated with an TDD
supplementary cell 1415, (may also be referred to as enhanced TDD
supplementary cell and the term "enhanced TDD supplementary
carrier" may be used in appropriate situations or as needed). The
TDD supplementary cell 1415 may be treated by the system as
additional bandwidth resources for both UL and DL. This additional
resource may be used opportunistically by the base station if the
RRM determines the need for it and an available channel may be
found. When an TDD supplementary cell 1415 is activated by the RRM,
the base station may have access to an additional TDD-like
component cell with which aggregation may be performed.
Effectively, DL carrier aggregation may occur over subframes in
which the TDD supplementary cell is in the DL direction, and UL
carrier aggregation may occur over subframes in which the TDD
supplementary cell is in the UL direction. During a gap 1420, the
TDD supplementary cell 1415 does not provide additional bandwidth
for aggregation. Aggregation may be performed by combining one or
more TDD supplementary cells with a licensed band PCC and zero or
more SCCs.
The TDD supplementary cell 1415 and the FDD licensed carriers 1405
and 1410 may inherently have different timing relationships for
various operations, most of them related to HARQ. In the case where
the TDD supplementary cell 1415 and licensed carriers 1405 and 1410
operate independently, these timing relations may not have any
impacts on the PHY and MAC layers of the system. However, to allow
cross-carrier scheduling of resources on the TDD supplementary cell
1415 from the licensed band carriers 1405 and 1410, procedures do
not currently exist within the 3GPP standards to define the
behavior of grants, retransmissions, and timing of power control
commands.
In order to resolve the discrepancy in timing, an enhanced TDD
supplementary cell 1415 may be used in which the procedures for
HARQ timing and PHY control channels, (PDCCH, PUCCH, and PHICH),
are described herein below. These procedures differ from those
defined in the 3GPP standards for a standard TDD CC, and the
differences may allow the enhanced TDD CC to function in the most
efficient way with an FDD licensed LTE system.
For the enhanced TDD frame structure, a dynamic UL/DL configuration
and dynamic frequency dependant guard period (GP), (shown as gap
1420), may be implemented. The TDD frame structure, (referred to as
a frame structure type 2), defined in the 3GPP standards, provide 7
different fixed UL/DL configurations that may be used in a static
fashion. Once configured, these configurations may be used for all
WTRUs throughout the cell and may not change. In HeNB deployments,
the number of WTRUs served by the HeNB may be quite smaller than a
macro-cell deployment. Therefore, the traffic load, (UL, DL, or
balanced), may change more frequently and in a more pronounced
fashion. Since the TIP UL/DL configuration in 3GPP may be fixed,
introducing a regular TDD component carrier in the LE bands results
in some limitations in the efficiency of the bandwidth use relative
to the traffic load.
One approach to mitigate the TDD limitation may be to dynamically
change the configuration of UL/DL in TDD by sending to the active
WTRU, through a RRC reconfiguration message or system information,
the new configuration information. As a result, in the enhanced TDD
supplementary cell, the RRM may control the UL/DL configuration of
the enhanced TDD supplementary cell based on the traffic load at
any given time. At any given time, one of the 7 UL/DL
configurations may be used for the enhanced TDD supplementary cell
in order to best suit the traffic load at the HeNB. For example,
for a DL heavy traffic load, (several WTRUs performing heavy
download of video, for example), the HeNB may configure UL/DL
configuration 5 for the enhanced TDD supplementary cell. This may
allow the UL/DL configuration to adjust to the traffic load over
the cell.
The system information about the enhanced TDD supplementary cell
UL/DL configuration would be sent by the PCC on the licensed band.
Following the sending of the signaling representing the change in
the UL/DL configuration, the base station may change the UL/DL
configuration, (and therefore the sequence of transmit and receive
subframes on the enhanced TDD supplementary cell), after a certain
number of sub frames. Potential candidates for the switching time
may be the frame boundary or the arrival of the first special
subframe on the enhanced TDD supplementary cell. These switch
points may avoid the switching from DL to UL that may occur when a
configuration is changed dynamically. Other switch points that
avoid a DL to UL transition may also be possible, and the signaling
which indicates the change of the UL/DL configuration may
potentially define the switch time as part of the messaging.
Idle mode WTRUs may not be impacted by a change in UL/DL
configuration, as camping on the primary carrier or multiple UL/DL
configurations may be preconfigured through an RRC message and
activated by a MAC control element (CE) message. In addition, since
carrier aggregation is not used in idle mode, the change of the
UL/DL configuration on these WTRUs may be transparent until RRC
connection, (at which time they receive the current UL/DL
configuration to be used). The UL/DL configuration of all
configured TDD supplementary cells may be signaled at the time of
RRC connection. Any changes to the UL/DL configuration may be
signaled through an RRC reconfiguration or through a dedicated SIB,
(since the UL/DL configuration may be applied to the entire system
utilizing the LE bands).
As illustrated in FIG. 14, TDD may require a gap (GP) 1420 in the
special sub frame 1422, (where a Downlink Pilot Timeslot (DwPTS)
1424 and an UL Pilot Timeslot (UpPTS) 1426 are included for
configuration and processing purposes), to avoid interference
during switching between UL and DL. In the enhanced TDD
supplementary cell, the GP duration may be configurable through RRC
reconfiguration or system information change to allow for the
configuration to dynamically adjust to the range of the TDD
supplementary cell as well as the frequency band of the unlicensed
spectrum being used, (the propagation characteristics of the signal
may change as the frequency is changed). A preconfigured OP value
per frequency band is also possible. This preconfigured GP may be
based on the expected cell size and propagation characteristics
over the LE channel in question, and be modified by an RRC message
when the frequency band of the supplementary carrier is
changed.
For the HARQ entity on the enhanced TDD supplementary cell, the FDD
HARQ timing may be used to define the operations of grants,
acknowledgements, and retransmissions on the supplementary carrier.
In order to allow the use of FDD-like timing for these operations
on the supplementary carrier, the presence of the PHY-layer control
channels present on the licensed carriers (PCC and SCC) may be
leveraged. Unlike a pure TDD system, the PHY-layer control channels
on the licensed FDD carriers may be present on every subframe and
may therefore be leveraged to allow FDD timing for operations
involving the enhanced TDD supplementary cell. In order to allow
this, the use of the PHY control channels on the enhanced TDD
supplementary carrier may be restricted so that the enhanced TDD
supplementary cell may not carry a PHICH channel, and all
acknowledgements to UL transmissions made by the WTRU may be sent
only on the PCC or SCC. The enhanced TDD supplementary cell may not
carry a PUCCH channel. The PUCCH may be transmitted on the PCC
only. The PDCCH may or may not be transmitted on the TDD
supplementary cell. FIG. 15 shows the physical channels that are
supported on each carrier of a system supporting a licensed exempt
operation.
UL grants addressed to the enhanced supplementary carrier may be
sent four subframes prior to when the grant takes effect. These
grants may be sent using the PDCCH on either the PCC/SCC, (assuming
cross-carrier scheduling), or on the supplementary carrier itself.
When cross-carrier scheduling is used, downlink control information
(DCI) format 0 is used to send the grant and may contain a carrier
indication field (CIF) to indicate the enhanced supplementary
carrier that carries the grant. The scheduler may ensure that an UL
grant is never sent four subframes prior to a DL subframe on the
enhanced TDD supplementary cell. These rules apply for both PDCCH
sent on the PCC/SCC and PDCCH sent on the supplementary
carrier.
As in regular TDD, DL allocations for resources on the enhanced TDD
supplementary cell may be sent on the same subframe where the
allocation takes place, and may therefore be sent on a subframe
where the supplementary carrier is a DL or special subframe.
The presence of control channels on every subframe, (due to
leveraging the licensed band), may allow a system aggregating an
enhanced TDD supplementary cell to send ACK/NACK n+4 subframes
following the actual data transmissions in both UL and DL. Although
ACK/NACK may be sent for data transmissions from the enhanced TDD
supplementary carrier after 4 subframes of the transmission, other
values for a fixed data to ACK delay may also be possible.
For DL transmission on the supplementary carrier, ACK/NACK may be
sent on either the PUCCH on the PCC or the physical UL shared
channel (PUSCH), (if a PUSCH is allocated in the given subframe).
Due to the availability of UL subframes on the PCC, the WTRU may
send ACK/NACK according to FDD timing. As with LTE Release 10,
PUSCH may be leveraged for sending ACK/NACK if a PUSCH is present
in the subframe where the feedback must be sent. The supplementary
carrier PUSCH may also be used to send ACK/NACK if PUSCH is not
allocated to the particular WTRU on PCC or SCC but is allocated on
the enhanced supplementary carrier for that subframe.
For UL transmission on the supplementary carrier, ACK/NACK may be
sent on the PHICH of the PCC or SCC. Due to the presence of DL
subframes on the PCC/SCC, the base station may send ACK/NACK using
the FDD timing. The PHICH may not be present on the supplementary
carrier due to the presence of UL subframes that do not carry the
PHICH and may limit the ability to transmit ACK/NACK using the FDD
timing.
Since retransmissions on the supplementary carrier depend on the
presence of a DL or UL subframe on those retransmissions, the n+4
FDD timing may not be applied in the case of retransmissions.
Physical random access channel (PRACH) procedures and structure in
TDD may be quite different from FDD. The PRACH procedures in LTE
may consist of 6 resource blocks (RBs) adjacent to the PUCCH in
predetermined subframes. For a given PRACH configuration (from
SIB2), mapping to specific subframes is different in TDD versus
FDD. In FDD, there may be at most one PRACH available per subframe.
In TDD, there may be multiple PRACH resources in a given subframe,
(to account for fewer UL subframes in a frame). The offset between
RACH resources in a subframe may be given by upper layers. Preamble
format 4 may be used only in TDD, (short preamble used to fit into
an UL pilot timeslot (UpPTS) of the special subframe).
For a system aggregating with an enhanced TDD supplementary cell,
the PRACH may be implemented in the primary cell which may be FDD.
Therefore, the configuration, timing, and procedure for PRACH may
follow the FDD case. However, the network may trigger an additional
PRACH procedure that is initiated on the supplementary carrier in
the event that timing alignment between primary and supplementary
carriers may be significantly different due to large frequency
separation. In this case, RRC reconfiguration associated to adding
the supplementary carrier may need to define the specific RACH
configuration to be used on the supplementary carrier which may
include an TDD RACH procedure. The RRC configuration that is sent
over the FDD carrier may specifically indicate that the RACH
configuration is specific to the TDD carrier. This particular type
of RACH may be triggered when the WTRU has data to send to the base
station, or when the base station has detected a timing drift
between the primary and supplementary carriers.
When performing PRACH on the TDD supplementary carrier, contention
resolution may take place on either the primary or supplementary
carriers in order to ensure a larger number of available PRACH
resources for the system.
Timing of UL power control for a PUSCH relative to a transmit power
control (TPC) command is different in TDD and FDD. A new entity may
be added in the base station that is aware of the timing difference
between the power control changes on the TDD and FDD carriers and
applies the appropriate transmit power control (TPC) command. If
cross carrier scheduling is supported, TPC commands for FDD or TDD
may be differentiated by adding a field to the PDCCH for a TPC
command or using a carrier specific schedule for TPC.
TDD may support bundling of multiple ACK/NACKs into a single
ACK/NACK to be sent in the UL subframe. FDD may not support this
mode, (single ACK is sent for each received transport block).
ACK/NACK bundling may be controlled by the downlink assignment
index (DAI) sent in the DCI on the PDCCH (2 bits). These two bits
may not be present in FDD mode DCI formats. When multiple serving
cells are configured, ACK/NACK bundling may not be performed, (but
multiplexing may still be possible). ACK/NACK repetition,
(configured by upper layers), in TDD mode may be applied for
ACK/NACK bundling and not for ACK/NACK multiplexing.
Cross-carrier scheduling of DL resources on the TDD supplementary
carrier may be allowed via the FDD carrier. For cross carrier
scheduling, the FDD carrier may need to include the DAI in the DCI
format. Additional complexity in blind decoding of PDCCH may be
required. Because ACK/NACK may be sent on PUCCH, bundling may need
to be supported on the FDD UL carrier, (the base station may need
to be able to decode the PUCCH related to the bundled information).
As a result, the bundling operation may be performed relative to
the transport blocks received in the TDD supplementary carrier, but
the bundled ACK/NACKs may be sent over the FDD carriers. In
addition, sending the bundled ACK/NACK over the TDD supplementary
carrier may be supported as well, using PUSCH. This is due to the
fact that, in a combined TDD/FDD design, ACK/NACK may not be sent
only on the primary carrier. Instead, ACK/NACK may be sent on a
secondary carrier if there is a PUSCH allocated on it, but no PUSCH
on the primary carrier.
Periodicity and timing of the sounding reference signal (SRS) may
be controlled by upper layer parameters and may be different
between TDD and FDD. An SRS may be transmitted in UpPTS in TDD
(UpPTS may be reserved for SRS and format 4 PRACH). Different
sub-frame configurations may be sent for each carrier when both TDD
and FUD are configured, (i.e., an TDD supplementary carrier or
cell, as appropriate). This additional SRS configuration may be
sent over the primary carrier. Fields may therefore be added to the
SRS configuration to identify whether the configuration corresponds
to TDD or FDD.
In contrast to FDD, in TDD, special frames may not have PUCCH
mapped to them. The PUCCH may be transmitted on the primary cell in
an FDD fashion.
For CA, a PHICH may be transmitted on the DL carrier that was used
to transmit the UL grant. The timing of responses to be expected on
the PHICH may differ in FDD and TDD. For FDD, a DL ACK/NACK may be
sent 4 subframes after the UT transmission, and in TDD this may be
variable. The mapping of PHICH resources may also differ. In FDD,
all frames may have the same number of PHICH resource elements in
the first OFDM symbol. In TDD, the number of PHICHs may depend on
the subframe. In TDD, the size of the PHICH may be adjusted based
on the UL/DL configuration, (UL-heavy configuration may have more
resource elements allocated to PHICH). PHICH collisions may be
considered for the case of cross-carrier scheduling, (resolved by
demodulation reference signal (DMRS) cyclic shift mechanism).
A PHICH may be sent on the licensed band, (in order to ensure n+4
timing for ACK/NACK on the enhanced TDD supplementary carrier). New
procedures may be required in order to define the PHICH resources
on the licensed band when scheduling of the supplementary carrier
is performed by the PDCCH on the supplementary carrier. A default
licensed carrier (the PCC) may be chosen for sending the PHICH in
this case, and the scheduler may avoid PHICH collisions through
smart scheduling. Alternatively, the PHICH may be sent on the
supplementary TDD carrier, (to make use of the adjustable PHICH
resources available on this carrier), if the n+4 HARQ timing is not
assumed.
Some DCI Formats on PDCCH may be different between TDD and FDD,
(e.g., DCI format 1 for FDD may be 3 bits for a HARQ process and 2
bits for DAI, while 4 bits for an HARQ process and no bits for DAI,
for TDD). If cross carrier scheduling is being used on the primary
carrier, a new PDCCH search space may be allocated in order to
decode both TDD and FDD DCI formats which may be separate from the
FDD PDCCH search space. This may simplify blind decoding of the
PDCCH.
Uplink grants may be signaled by the PDCCH using DCI format 0. In
FDD, a UL grant may start 4 subframes after DCI format 0 is
received, (DCI format 0 may also be different for TDD/FDD). In TDD,
the UL index in DCI format 0 may specify the timing of the grant.
In order to do cross-carrier scheduling in the UL with a LE
supplementary TDD carrier, a new TDD DCI format 0 may be used to be
better aligned with the FDD DCI format. The information from the
DCI sent on the FDD carrier may specify both whether the UL grant
is specific to the FDD or TDD carrier, and when it may be scheduled
when it is specific to the TDD carrier.
To support DL heavy CA configurations, PUCCH format 3 may be used
to allow a larger number of bits for ACK/NACK, (when format 1b with
channel selection does not have sufficient bits for the required
ACK). In FDD, 10 bits may be allocated in PUCCH format 3. In TDD,
20 bits may be allocated in PUCCH format 3. The ACK/NACK may be
treated for supplementary TDD carrier as an FDD supplementary
carrier. There may not be a need to implement ACK/NACK bundling, as
it is the case for TDD, as there is always an UL FDD carrier active
(primary carrier) in this approach.
If an TDD carrier is used, the way in which system information may
be interpreted for CQI reporting may have to be different for the
TDD or FDD carrier, (alternatively, separate system information
(SI) for FDD and TDD may be needed). Mixing TDD and FDD may be more
complex for the scheduler as well, which may need to be able to
handle two different schedules of TDD and FDD to come up with the
DL allocation decisions. Upper layer event reporting and
measurements may also need to be modified given different timing
for CQI reports coming from the TDD and FDD carrier.
Described herein are coexistence embodiments. Spectrum sharing
among secondary users may require an effective use of the LE bands.
If it is not coordinated well, the hands may be either left
unoccupied, resulting in a waste of frequency bands, or heavily
accessed by secondary users, causing significant interference with
each other. Therefore, a well designed coexistence mechanism is
desirable to enable an effective usage of the LE bands and improve
the communication quality of the secondary networks.
Referring back to FIG. 1, a database enabled coexistence solution
may be incorporated in a network including a coexistence manager
570 and a policy engine 574 that may be used to coordinate
opportunistic use of LE bands with other secondary users/networks.
The coexistence manager 570 of a given network may include
interfaces to the TVWS database 525 and coexistence database 572,
network devices and coexistence managers of other networks.
Location based LE band allocations may either be distributed to
base stations/HeNBs or centralized at the core network. The policy
engine 574 may generate and enforce polices based on database
information and operator defined rules.
A centralized hierarchical coexistence database management solution
maybe used. A local database, for example coexistence database 572
in FIG. 5, which may be core network based, may be used to
coordinate secondary usage within a given operators network, while
an Internet based database may be used to coordinate secondary
usage with external, users/networks. Alternatively, a distributed
approach may be implemented where there is no centralized entity to
make spectrum allocation decisions. In this approach, the eNB/HeNB
may be responsible for accessing the coexistence database,
processing the spectrum sharing negotiation with neighbor
eNB/HeNBs, and making spectrum allocation decisions.
A spectrum sensing coexistence solution may be implemented where
the network may rely on spectrum sensing results to coexist with
other secondary networks. For this approach, a new entity, for
example sensing co-processor/enhanced sensing 550 in FIG. 5, at the
eNB/HeNB may negotiate access to LE bands by exchanging sensing and
channel occupancy information with neighboring eNBs/HeNBs.
Alternatively, a centralized approach may be implemented based on
spectrum sensing where a central entity in the core network may
process the spectrum sensing results received from HeNBs/eNBs and
make decisions about eNB/HeNB channel assignments.
A contention based coexistence solution may be implemented by
performing carrier sensing for clear channel assessment (CCA) prior
to commencing with transmissions. The eNB may maintain control of
grant and scheduling of transmission opportunities. However,
transmissions may be "gated" by the CCA.
Described herein is supplementary cell configuration and activation
at an HeNB. Once the HeNB decides that it may activate a new
supplementary cell, as the operating cells controlled by the HeNB
are experiencing congestion, it first may seek the channel usage
information from the coexistence manager, which is triggered by a
spectrum request. The spectrum allocation of the HeNB may select
the channel which triggers within the DSM RRM a series of events to
correctly configure and activate the new supplementary cell. Cell
configuration at the HeNB refers to determining all the cell
parameters including defining the resources to be used as well as
configuring the different LTE protocol layers for that specific
cell in the HeNB. Cell activation at the HeNB refers to starting
the transmission and reception at the HeNB.
The configuration phase of the supplementary cell may determine the
type of channels it will operate in, (sublicensed, available or PU
assigned), determine the requirement of coexistence gaps, configure
the sensing toolbox of the HeNB, select the amount of resources
allocated to UL and DL, (i.e., TDD configuration no. 1-7 if an TDD
frame structure; operating mode DL only, UL only or shared if an
FDD frame structure). In the case of an TDD frame structure, a
transmitting power level is determined, and RRM functions to
consider the new SuppCC as a new resource, (packet scheduler, radio
bearer control (RBC), and the like), may be configured.
Transmission/reception in the supplementary cell may be started.
Although mandatory control information transmitted over the
supplementary cell may be reduced, some control information such as
PSCH and SSCH may be still required to be broadcast. A cell
activation procedure for a set of connected WTRUs may be
initiated.
Once the HeNB decides that is may release a supplementary cell, as
the operating cells controlled by the HeNB are experiencing less
load, the supplementary cell is experiencing an unacceptable level
of interference, a primary user was detected in the case of a PU
assigned channel or it receives a request from the CM to evacuate
the channel, this may trigger within the DSM RRM a series of events
to correctly release the new supplementary cell. RRM functions to
consider that the resources associated with the released SuppCC are
no longer available, (packet scheduler, RBC, and the like), may be
configured. A deactivation command (e.g., MAC CE command), may be
sent to all connected WTRUs currently active on this supplementary
cell. An RRC reconfiguration may be sent to all current configured
WTRUs on this supplementary cell to release the supplementary cell.
The CM may be informed that the supplementary cell is released. New
requirements may be determined for measurement gaps. A sensing
toolbox of the HeNE may be configured, and the transmitting on the
supplementary cell may be stopped.
Embodiments
1. A method of aggregating carriers, comprising providing an
aggregating cell configured for operation in a frequency division
duplex (FDD) licensed spectrum.
2. The method of embodiment 1, further comprising aggregating the
aggregating cell with at least one licensed exempt (LE)
supplementary cell operating in a time sharing mode for uplink (UL)
and downlink (DL) operations.
3. The method of any of the above embodiments, wherein the at least
one LE supplementary cell is an FDD supplementary cell dynamically
configurable between an UL only mode, a DL only mode, and a shared
mode to match requested UL and DL traffic ratios.
4. The method of any of the above embodiments, wherein for the
shared mode, the at least one LE supplementary cell is toggled
between UL and DL at a toggling interval to match requested UL and
DL traffic ratios.
5. The method of any of the above embodiments, wherein a sharing
mode pattern is based on sub-frame timing.
6. The method of any of the above embodiments, wherein a sharing
mode pattern repeats at a multiple of a number of hybrid automatic
repeat request (HARQ) processes used by the aggregating cell.
7. The method of any of the above embodiments, wherein HARQ
feedback is transmitted on one of the aggregating cell and the LE
supplementary cell.
8. The method of any of the above embodiments, wherein HARQ
feedback is bundled.
9. The method of any of the above embodiments, wherein a
configuration change is triggered by one of a radio resource
control (RRC) message, a medium access control (MAC) control
element (CE) command transmitted over the aggregating cell or a
dedicated system information block (SIB) transmitted over the
aggregating cell.
10. The method of any of the above embodiments, wherein multiple LE
supplementary cells are one of independently or dependently
configured.
11. The method of any of the above embodiments, wherein the at
least one LE supplementary cell is a time division duplex (TDD)
supplementary cell.
12. The method of any of the above embodiments, wherein the TDD
supplementary cell is dynamically configurable between multiple TDD
configurations a given number of sub-frames after configuration
change signaling.
13. The method of any of the above embodiments, further comprising
providing a guard period for UL/DL to DL/UL transitions that is
dynamically configurable based on at least one of frequency, range,
or size of the TDD supplementary cell.
14. The method of any of the above embodiments, wherein timing for
grants and hybrid automatic repeat request (HARQ) feedback is based
on the aggregating cell FDD timing.
15. The method of any of the above embodiments, wherein the
aggregating cell transmits at least one of HARQ feedback, grants
and channel state information for the TDD supplementary cell.
16. The method of any of the above embodiments, further comprising
triggering additional random access resources on the TDD
supplementary cell on detecting a timing drift between the TDD
supplementary cell and the aggregating cell.
17. The method of any of the above embodiments, further comprising
providing a coexistence capability for coordinating operations
between the LE supplementary cell with at least one of other
networks and users operating in a same LE channel.
18. The method of any of the above embodiments, further comprising
providing coexistence gaps to permit the other networks and users
operating in the same LE channel as the LE supplementary cell to
access the same LE channel.
19. A base station for licensed exempt spectrum aggregation,
comprising a dynamic spectrum management radio resource manager
(RRM) configured to receive cognitive sensing results from a
sensing toolbox and to configure operation of the sensing
toolbox.
20. The base station of embodiment 19, further comprising the REM
configured to control physical layer and a medium access layer
configurations that provide coexistence gaps to permit other
networks and users operating in a same licensed exempt (LE) channel
as a LE supplementary cell to access the same LE channel.
21. The base station of any of embodiments 19-20, further
comprising the RRM configured to control a radio resource
controller configuration to detect primary users and transition
between different frequency division duplex (FDD) modes or time
division duplex (TDD) uplink and downlink configurations.
22. The base station of any of embodiments 19-21, further
comprising a coexistence enabler interface configured to
communicate between a coexistence manager and cognitive networks,
wherein coexistence manager reconfiguration commands are translated
into network-specific reconfiguration commands and transmitted to
the cognitive network for reconfiguration, wherein the RRM receives
translated coexistence manager reconfiguration commands from the
coexistence enabler interface.
23. A wireless transmit/receive unit, comprising a radio resource
controller (RRC) and a medium access controller (MAC) configured to
receive configuration messages, the RRC and MAC being configured to
provide coexistence gaps to permit other networks and users
operating in a same LE channel as a LE supplementary cell to access
the same LE channel, wherein a physical layer is configured by one
of the RRC or MAC according to the configuration message.
24. The WTRU of embodiment 23, further comprising the RRC being
configured to control a sensing toolbox to perform cognitive
sensing measurements and support the coexistence gaps for
primary/secondary user detection.
25. The WTRUI of any of embodiments 23-24, further comprising the
RRC being configured to detect primary users and transition between
different frequency division duplex (FDD) modes or time division
duplex (TDD) uplink and downlink configurations.
26. A management system, comprising a coexistence manager (CM)
entity configured to manage inter-base stations as well as
inter-operator coexistence operation.
27. The management system of embodiment 25, further comprising the
CM configured to receive sensing and usage data, and licensed
exempt (LE) spectrum information.
28. The management system of any of embodiments 26-27, further
comprising the CM configured to process and forward the usage data
to requesting base station.
29. The management system of any of embodiments 26-28, further
comprising the CM configured to maintain a map of networks to
identify conflicts and coexistence operations based on at least the
sensing and usage data, and LE spectrum information.
30. The management system of any of embodiments 26-29, further
comprising the CM configured to transmit LE availability
information based on at least the sensing and usage data, and the
LE spectrum information.
31. The management system of any of embodiments 26-30, wherein a
ranking of available channels is sent to the base station.
32. A method comprising communicating via a primary carrier and a
secondary carrier.
33. The method of any of embodiments 1-18 and 32, wherein the
primary carrier is in the FDD licensed spectrum and the secondary
carrier is in the licensed exempt spectrum.
34. The method of any of embodiments 1-18 and 32-33, further
comprising dynamically changing the supplementary carrier to
aggregate in the downlink or uplink.
35. The method of any of embodiments 1-18 and 32-34, further
comprising dynamically changing the direction of aggregation
through a MAC CE command.
36. The method of any of embodiments 1-48 and 32-35, wherein the
MAC CE command activates the supplementary carrier in one direction
and deactivates it in another.
37. The method of any of embodiments 1-18 and 32-36, further
comprising providing a guard period (GP) for dynamic FDD priory to
a frame boundary when switching the supplementary carrier from DL
to UL or vice versa.
38. The method of any of embodiments 1-18 and 32-37, wherein the GP
is configured based on the range or size of a cell.
39. The method of any of embodiments 1-18 and 32-38, wherein the GP
is configured dynamically via RRC signaling.
40. The method of any of embodiments 1-18 and 32-39, further
comprising providing a PHICH allocation sent over the RRC
reconfiguration message while configuring the supplementary
carrier.
41. The method of any of embodiments 1-18 and 32-40, wherein the
PHICH configurations are changed when the supplementary carrier is
reconfigured.
42. The method of any of embodiments 1-18 and 32-41, wherein the
PDCCH in the licensed band is modified based on PHICH
allocations.
43. The method of any of embodiments 1-18 and 32-42, wherein on a
condition that an unlicensed band carrier is set to DL only, the
unlicensed band UL control information is sent over the primary
carrier.
44. The method of any of embodiments 1-18 and 32-43, further
comprising dynamically changing the configuration of UL/DL in TDD
using an RRC reconfiguration message.
45. The method of any of embodiments 1-18 and 32-44, further
comprising providing a GP in the special sub frame for the TDD
supplementary carrier.
46. The method of any of embodiments 1-18 and 32-45, further
comprising dynamically adjusting to the range of the cell as well
as the frequency band of the unlicensed spectrum being used.
47. The method of any of embodiments 1-18 and 32-46, further
comprising providing a preconfigured GP value per frequency
band.
48. The method of any of embodiments 1-18 and 32-47, wherein
periodicity and timing of a Sounding Reference Signal (SRS) are
controlled by upper layer parameters and are different between TDD
and FDD.
49. The method of any of embodiments 1-18 and 32-48, further
comprising sending different subframe configurations for each
carrier when both TDD and FDD configured.
50. The method of any of embodiments 1-18 and 32-49, further
comprising transmitting the PUCCH only on the primary cell in an
FDD fashion.
51. The method of any of embodiments 1-18 and 32-50, further
comprising triggering additional PRACH on the supplementary
carrier.
52. The method of any of embodiments 1-18 and 32-51, wherein an RRC
configuration that is sent over the FDD carrier indicates the RACH
configuration is specific to the TDD carrier.
53. The method of any of embodiments 1-18 and 32-52, wherein during
performance of a PRAM on the secondary carrier (TDD), contention
resolution occurs on either the primary or supplementary carrier in
order.
54. The method of any of embodiments 1-18 and 32-53, further
comprising providing a new entity in the eNB that is aware of the
timing difference between the power control changes on the TDD and
FDD carriers and applying the appropriate TPC command.
55. The method of any of embodiments 1-18 and 32-54, further
comprising allowing cross-carrier scheduling of downlink resources
on the TDD supplementary carrier aria the FDD carrier.
56. The method of any of embodiments 1-18 and 32-55, further
comprising sending bundled ACK/NACKs over the primary carrier.
57. The method of any of embodiments 1-18 and 32-56, further
comprising sending bundled ACK/NACKs over the secondary
carrier.
58. The method of any of embodiments 1-18 and 32-57, further
comprising send the PHICH on the supplementary TDD carrier.
69. The method of any of embodiments 1-18 and 32-58, further
comprising allocating a new PDCCH search space in order to decode
both TDD and FDD DCI formats which will be separate from the FDD
PDCCH search space.
60. The method of any of embodiments 1-18 and 32-59, wherein UL
grants are signaled by the PDCCH using DCI format 0.
61. The method of any of embodiments 1-18 and 32-60, further
comprising providing a new TDD DCI format 0 better aligned with the
FDD DCI format.
62. The method of any of embodiments 1-18 and 32-61, further
comprising treating to treat ACK/NACKs for supplementary TDD
carrier as an FDD supplementary carrier.
63. The method of any of embodiments 1-18 and 32-62, wherein upper
layer event reporting and measurements are modified given different
timing for CQI reports coming from the TDD and FDD carrier.
64. The method of any of embodiments 1-18 and 32-63, further
comprising providing a Coexistence Manager and Policy Engine to
coordinate opportunistic use of Licensed Exempt bands with other
secondary users/networks.
65. The method of any of embodiments 1-18 and 32-64, wherein the
Coexistence Manager of a given network includes interfaces to the
TVWS/Coexistence databases, network devices and Coexistence
Managers of other networks.
66. The method of any of embodiments 1-18 and 32-65, further
comprising a Policy Engine to generate and enforce polices based on
database info and operator defined rules.
67. The method of any of embodiments 1-18 and 32-66, wherein a new
entity at the eNB/HeNB negotiates access to Licensed Exempt
bands.
68. The method of any of embodiments 1-18 and 32-67, wherein
carrier sensing is performed for Clear Channel Assessment (CCA)
prior to commencing with transmissions.
69. A method of aggregating carriers comprising a frequency
division duplex (FDD) primary cell aggregating a supplementary
carrier.
70. The method of any of embodiments 1-18, 32-67 and 69, wherein
the supplementary carrier is a dynamic FDD supplementary
carrier.
71. The method of any of embodiments 1-18, 32-67 and 69-70, wherein
the supplementary carrier is a licensed exempt carrier.
72. The method of any of embodiments 1-18, 32-67 and 69-71, wherein
the supplementary carrier is a time division duplex (TDD)
supplementary carrier.
73. The method of any of embodiments 1-18, 32-67 and 69-72, wherein
the FDD primary cell includes uplink and downlink component
carriers (CCs).
74. The method of any of embodiments 1-18, 32-67 and 69-73, wherein
the CCs are activated or deactivated as needed.
75. The method of any of embodiments 1-18, 32-67 and 69-74, wherein
one of the CCs is deactivated between two time slots.
76. The method of any of embodiments 1-18, 32-67 and 69-75, wherein
the CCs are in a downlink-only mode.
77. The method of any of embodiments 1-18, 32-67 and 69-76, wherein
the CCs are in an uplink only mode.
78. The method of any of embodiments 1-18, 32-67 and 69-77, wherein
the CCs are in a shared mode.
79. A home evolved Node-B (HeNB) comprising a dynamic spectrum
management (DSM) radio resource management (RRM) entity.
80. The HeNB of embodiment 79, further comprising a sensing toolbox
configured to perform and process cognitive sensing on television
white space (TVWS) and licensed exempt (LE) spectrum and reporting
the results to the DSM RRM entity.
81. The HeNB of any of embodiments 79-80, further comprising a
physical (PHY) layer.
82. The HeNB of any of embodiments 79-81, further comprising a
medium access control (MAC) layer.
83. The HeNB of any of embodiments 79-82, further comprising a
radio link control (RLC) layer.
84. The HeNB of any of embodiments 79-83, further comprising a
packet data convergence protocol (PDCP) layer.
85. The HeNB of any of embodiments 79-84, further comprising a
radio resource control (RRC) layer.
86. A wireless transmit/receive unit (WTRU) comprising a dynamic
spectrum management (DSM) radio resource management (RRM)
entity.
87. The WTRU of embodiment 86, further comprising a sensing toolbox
configured to perform and process cognitive, sensing on television
white space (TVWS) and licensed exempt (LE) spectrum and reporting
the results to the DSM RRM entity.
88. The WTRU of any of embodiments 86-87, further comprising a
physical (PRY) layer.
89. The WTRU of any of embodiments 86-88, further comprising a
medium access control (MAC) layer.
90. The WTRU of any of embodiments 86-89, further comprising a
radio link control (RLC) layer.
91. The WTRU of any of embodiments 86-90, further comprising a
radio resource control (RRC) layer.
92. A home evolved management system (HeMS) comprising coexistence
manager (CM) entity.
93. The HeMS of embodiment 91, further comprising an operator's
coexistence database.
94. The HeMS of any of embodiments 91-93, further comprising a
plurality of policies, wherein the HeMS communicates with a
television white space (TVWS) database via a coexistence discovery
and information server (CDIS).
95. A method of aggregating carriers comprising aggregating
licensed carriers with at least one supplementary component carrier
of a primary cell, wherein a guard period between uplink and
downlink transitions are altered based on a frequency of operation
of the supplementary component carries.
96. An apparatus comprising a WTRU configured to perform any one of
the above-specified methods.
97. A computer readable medium having instructions stared thereon
that when executing by a WTRU cause the WTRU to perform any one of
the above-specified methods.
98. A wireless receive/transmit unit (WTRU) configured to perform
the method of any one of embodiments 1-18, 32-77 and 95.
99. The WTRU as in embodiment 98, further comprising a
transceiver.
100. The WTRU as in any one of embodiments 98-99, further
comprising a processor in communication with a transceiver.
101. The WTRU as in any one of embodiments 98-100, wherein a
processor is configured to perform the method of any one of
embodiments 1-18, 32-77 and 95.
102. A network node configured to perform the method of any one of
embodiments 1-18, 32-77 and 95.
103. A Node-B configured to perform the method of any one of
embodiments 1-18, 32-77 and 95.
104. An integrated circuit configured to perform any one of
embodiments 1-18, 32-77 and 95.
Although features and elements are described above in particular
combinations, one of ordinary skill in the art will appreciate that
each feature or element may be used alone or in combination with
any of the other features and elements. In addition, the
embodiments described herein may be implemented in a computer
program, software, or firmware incorporated in a computer-readable
medium for execution by a computer or processor. Examples of
computer-readable media include electronic signals, (transmitted
over wired or wireless connections), and computer-readable storage
media. Examples of computer-readable storage media include, but are
not limited to, a read only memory (ROM), a random access memory
(RAM), a register, a cache memory, a semiconductor memory device, a
magnetic media, (e.g., an internal hard disc or a removable disc),
a magneto-optical media, and an optical media such as a compact
disc (CD) or a digital versatile disc (DVD). A processor in
association with software may be used to implement a radio
frequency transceiver for use in a WTRU, UE, terminal, base
station, Node-B, eNB, HNB, HeNB, AP, RNC, wireless router or any
host computer.
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